Minimum Safe Altitude Warning Presented to: Pan American Aviation Safety Summit; Sao Paulo, Brazil By: Date: Glenn W. Michael Manager, CAST International Operations April 21, 2010
MSAW Overview A general overview of MSAW Accident Investigation impacts on MSAW Air Traffic Control procedures and MSAW MSAW Development 2
Controlled Flight into Terrain (CFIT) is Four words meaning. 3
Controlled Flight Into Terrain (CFIT) A controlled-flight-into-terrain (CFIT) accident is one in which an otherwise serviceable aircraft, under the control of the crew, is flown (unintentionally) into terrain, obstacles or water, with no prior awareness on the part of the crew of the impending collision 4
Wreckage of KA Flight 801 NTSB 5
Proximity to UNZ VOR 6
On-Board Barriers Instrument Landing System (ILS) Glideslope out of service since July Outer/Middle marker indicators suppressed Published approach procedures Pilot misunderstood/disregarded DME fixes. Ground Proximity Warning System (GPWS) Commonly ignored due to nuisance warnings Pilot not flying, flight engineer Didn t challenge approach soon enough 7
Ground-based Barriers System Inhibited by FAA due to nuisance warnings 8
Effectiveness of MSAW NTSB/FAA simulation indicated that, without the inhibition, MSAW would have generated an alert 64 seconds before impact. NTSB: This would have been sufficient for the controller to advise KA 801. (p. 174) 9
NTSB concluded: Contributing to the accident was the s (FAA) intentional inhibition of the minimum safe altitude warning system (MSAW) at Guam and the agency s failure to adequately manage the system. 10
As Former FAA Administrator Blakey said, "We need to change one of the biggest historical characteristics of aviation safety improvements our reactive nature. We must get in front of accidents, anticipate them, and use hard data to detect problems and disturbing trends." 11
Mitigations (Safety Enhancements) The measures taken or proposed to eradicate the hazard or to reduce the probability or the severity of a risk. 12
Order of Precedence for Hazard Mitigation Modify the system design the hazard out Physical guards or barriers prevent the risk from occurring Warning or alert signal Procedural and training change Advise people placards, notices, brief all pilots, etc. 13
Eastern Airlines Flight 401 MSAW Origination 14
Eastern Airlines Flight 401 15
Origin of MSAW 16
Origin of MSAW 17
Ground Based Prevention of CFIT ATC Safety Net What ground-based intervention would have prevented the accident? Automated tools provide the means for ATC to strengthen overall defenses against CFIT (MSAW) 18
A function designed solely as a controller aid in detecting potentially unsafe aircraft proximity to terrain/obstructions Generates and alert to the controller when a pilot is below, or is predicted to be below, a specified altitude Must be adapted specifically for each RADAR system 19
(cont) Types of MSAW Processing General Terrain Monitoring Approach Path Monitoring 20
(cont) General Terrain Monitoring Current Alarm Presently less than 500 feet above terrain map Prediction Alarm Pilot will be less than 500 feet above terrain map within 30 seconds Projection Alarm Pilot will be unable to clear all obstacles within eight minutes flying time on present course at a five degree climb angle 21
MSAW General Monitoring Minimum Safe Altitude (MSA) 500 Threshold Terrain Clearance Altitude 22
(cont) Approach Path Monitor Current Pilot is currently below the calculated APM alarm slope altitude Prediction Pilot is predicted to be 100 feet below the calculated APM alarm slope altitude within the next 15 seconds 23
MSAW Approach Path Monitoring Glideslope Path Alarm Trigger Area (100 below glideslope path) 1 nm Runway
MSAW: Safety-Critical? FAA: Safe operation of aircraft is ultimately pilots responsibility. MSAW is an aid to Air Traffic Controllers MSAW only ground-based CFIT barrier 25
MSAW Phraseology LOW ALTITUDE ALERT (call sign), CHECK YOUR ALTITUDE IMMEDIATELY. THE Minimum IFR Altitude is (altitude) THE (as appropriate) MDA/DH IS (altitude). 26
MSAW Procedures and phraseology ICAO order Procedures for Air Navigation Services Air Traffic Management (PANS-ATM) Document 4444 Chapter 15 Para. 15.6.4 Minimum Safe Altitude Warning (MSAW) Procedures 27
Thank You Questions??????? 28